This application seeks support for an interdisciplinary predoctoral and postdoctoral fellowship program that joins together three highly successful, research fellowship training programs from Boston University School of Medicine and adds a fourth from Boston University School of Public Health. The principal objective of the program is to train emerging researchers in three overlapping domains: (1) how health reform impacts urban, low-income families; (2) conduct research that improves the quality of care provided to low-income populations, and (3) provide trainees the knowledge and skills to shape future health policy for vulnerable populations. Since 2000, the combined programs have had 45 graduates in their research tracks of whom two-thirds are currently clinician-investigator faculty in Departments of Family Medicine, Pediatrics, Internal Medicine, or Health Policy/Management in the nation's medical schools, teaching hospitals and schools of public health. Moreover, three-quarters of them devote at least 50% time to their research careers. Their publication and grant record indicates that they have already successfully launched their research careers. These publications substantially address the health care issues and unmet health care needs of our target population: vulnerable people who reside in inner-city urban areas. The programs have individually received prior training grants, including over ten HRSA Title VII Faculty Development Program Grant Awards, most recently in 2011-2016. Together the departments have over $27 million in current research grants, and program faculty members have extensive records of successful research mentoring. They include leaders in healthcare disparities, healthcare reform, prevention science, economics and health policy. We seek support for four postdoctoral fellows and two predoctoral fellows in each funding year. The support for this innovative training opportunity will facilitate health services research training for future generations that is interdisciplinary and informed by primary care and public health perspectives. The program attracts qualified trainees, provides excellent training and guidance, and our curriculum is proven to launch graduates into productive academic research careers. The knowledge and skills provided in the training program will assist our graduates to perform research that will inform policy makers about the impact of health reform on urban, low- income families, and will provide important information that will be used to improve the quality of care provided to all Americans, especially those most in need.